Proposal
(119) to South American
Classification Committee
Change
linear sequence of genera in the Troglodytidae
Effect on South American
CL: This rearrange the sequence of genera in the
Troglodytidae to conform to recent genetic data on their phylogeny.
Background: Our
linear sequence of genera in the Troglodytidae is maintained largely through
historical momentum from the last 40 years. Early in the 1900s (e.g., Ridgway),
the sequence tended to begin with Cistothorus and Thryothorus.
In the mid-1900s, sequences tended to lead with Troglodytes.
Starting with Paynter's (1960) Peters Checklist, the sequence began with Campylorhynchus and
ended with Cyphorhinus. Paynter's sequence received input from
Selander, who was studying Campylorhynchus at the time, but I
cannot find any explicit rationale for that sequence or any other sequence.
New information: Barker
(2004) analyzed sequence data from mt DNA (cytochrome b) and nuclear DNA
(intron 4 of beta fibrinogen) from most genera in the Troglodytidae.
Get a pdf of Barker (2004)
at:
http://www.tc.umn.edu/~barke042/pdfs/Barker04.pdf
Barker found strong
support (Fig. 3 + 4) for two major clades, and a number of subgroups:
I. First major clade:
Microcerculus + Salpinctes
+ Catherpes + Hylorchilus (note: root of the wren tree was
tentatively thought to be between Salpinctes and other wrens
[Barker, 2004], but current data place it between clade I and clade II [strong
support from multiple nuclear genes, K. Barker unpublished data])
II. Second major clade:
(a) Odontorchilus
(b) Troglodytes +
Cistothorus
(c) Campylorhynchus
+ Thryomanes +Thryothorus +Henicorhina + Cyphorhinus + Cinnycerthia
other branches with
strong support:
(d) Campylorhynchus +
(Thryomanes +Thryothorus ludovicianus)
(e) Henicorhina +
Cyphorhinus + Cinnycerthia + other Thryothorus
Thryothorus is
polyphyletic, but insufficient taxon-sampling prevents further
rearrangement and presumed revival of Thryophilus at this
time.
Analysis:
Although additional, ongoing sampling by Keith will likely produce some further
changes in the branching pattern, it's clear that our current linear sequence
does not reflect phylogeny in the family.
Keith and I propose the
following linear sequence (South America genera only) to best reflect
historical relationships among genera. Other permutations are, of course,
possible, but this one minimizes disturbance of the historical sequence.
Microcerculus
Odontorchilus
Troglodytes
Cistothorus
Campylorhynchus
Thryothorus
Cinnycerthia
Henicorhina
Cyphorhinus
Regardless of whatever
future adjustments we need to make, this one is supported by genetic data, in
contrast to the traditional sequence, which lacks any explicit justification.
This proposal sailed through the South American Checklist Committee with little
comment, but that might at least in part be due to fewer wren genera there,
particularly the absence of Uropsila and Hylorchilus,
missing taxa in Keith's sample.
Recommendation: I see
no reason to perpetuate a misleading classification any longer, and I think the
only reasons not to vote YES would be to wait for greater taxon-sampling,
especially within Thryothorus.
Literature Cited:
BARKER, F. K. 2004.
Monophyly and relationships of wrens (Aves: Troglodytidae): a congruence
analysis of heterogeneous mitochondrial and nuclear DNA sequence data.
Molecular Phylogenetics and Evolution 32: 486-504.
Van
Remsen, April 2004, with input and comments from Keith Barker
_____________________________________________________________________________________
Voting chart for SACC proposals
100-218
Comments from Nores: "SI estoy de acuerdo, ya que los resultados
provenientes de dos tipos de análisis genéticos coinciden. El único cambio que
yo haría a la secuencia sería poner Cinnycerthia antes
que Thryothorus y no entre medio de Thryothorus y Henicorhina.
Me parece que Thryothorus y Henicorhina son
muy afines como para separarlos con un género que aparentemente no es tan
afín."